scholarly journals Calcium signalling: NAADP comes out of the shadows

2003 ◽  
Vol 373 (1) ◽  
pp. e3-e4 ◽  
Author(s):  
Guy A. RUTTER
Keyword(s):  
Nicotinic Acid ◽  
Recent Work ◽  
Molecular Mechanisms ◽  
Second Messengers ◽  
Calcium Signalling ◽  
Extracellular Stimuli

The molecular mechanisms through which extracellular stimuli mobilize intracellular Ca2+ stores are still incompletely understood. Recent work suggests that nicotinic acid–adenine dinucleotide phosphate (NAADP) can finally join the ranks of genuine Ca2+-mobilizing second messengers.

Examining a new role for zinc in regulating calcium release in cardiac muscle

2015 ◽  
Vol 43 (3) ◽  
pp. 359-363 ◽  
Author(s):  
Samantha J. Pitt ◽  
Alan J. Stewart
Keyword(s):  
Cardiac Muscle ◽  
Mammalian Cells ◽  
Molecular Mechanisms ◽  
Calcium Release ◽  
Biological Significance ◽  
Calcium Signalling ◽  
Signalling Molecule ◽  
Extracellular Stimuli ◽  
Recent Attention

It is well established that mammalian cells contain a small but measurable pool of free or labile zinc in the cytosol that is buffered in the high picomolar range. Recent attention has focused on the fact that this pool of free zinc has signalling effects that can be evoked through extracellular stimuli posing the question as to whether zinc should be regarded as a second messenger. Our knowledge of the targets, the biological significance and the molecular mechanisms of zinc signalling is limited but recent evidence suggests that zinc homoeostasis may be intimately linked to intracellular calcium signalling. In this review, we discuss the role of zinc as an intracellular signalling molecule with an emphasis on the potential role of zinc in shaping calcium-dynamics in cardiac muscle. We also consider the evidence that the cardiac ryanodine receptor (RyR2) is a potential zinc signalling target.

scholarly journals Differential regulation of nicotinic acid–adenine dinucleotide phosphate and cADP-ribose production by cAMP and cGMP

1998 ◽  
Vol 331 (3) ◽  
pp. 837-843 ◽  
Author(s):  
Heather L. WILSON ◽  
Antony GALIONE
Keyword(s):  
Nicotinic Acid ◽  
Sea Urchin ◽  
Calcium Release ◽  
Second Messengers ◽  
Differential Regulation ◽  
Sea Urchin Egg ◽  
Inositol 1,4,5 Trisphosphate ◽  
Extracellular Stimuli ◽  
Camp And Cgmp ◽  
Temperature Optima

The sea urchin egg has been used as a system to study calcium-release mechanisms induced by inositol 1,4,5-trisphosphate (IP3), cADP-ribose (cADPR), and more recently, nicotinic acid–adenine dinucleotide phosphate (NAADP). In order that cADPR and NAADP may be established as endogenous messengers for calcium release, the existence of intracellular enzymes capable of metabolizing these molecules must be demonstrated. In addition, intracellular levels of cADPR and NAADP should be under the control of extracellular stimuli. It has been shown that cGMP stimulates the synthesis of cADPR in the sea urchin egg. The present study shows that the sea urchin egg is capable of synthesizing and degrading NAADP. cADPR and NAADP synthetic activities appear to be separate, with different cellular localizations, pH and temperature optima. We suggest that in the sea urchin egg, cADPR and NAADP production may be differentially regulated by receptor-coupled second messengers, with cADPR production being regulated by cGMP and NAADP production modulated by cAMP.

scholarly journals Intercellular calcium signalling between chondrocytes and synovial cells in co-culture

1998 ◽  
Vol 329 (3) ◽  
pp. 681-687 ◽  
Author(s):  
Paola D'ANDREA ◽  
Alessandra CALABRESE ◽  
Micaela GRANDOLFO
Keyword(s):  
Gap Junctions ◽  
Intercellular Communication ◽  
Structural Changes ◽  
Articular Chondrocytes ◽  
Cell Metabolism ◽  
Second Messengers ◽  
Calcium Signalling ◽  
Cell Types ◽  
Synovial Cells ◽  
Cell Coupling

Intercellular communication allows the co-ordination of cell metabolism between tissues as well as sensitivity to extracellular stimuli. Paracrine stimulation and cell-to-cell coupling through gap junctions induce the formation of complex cellular networks that favour the intercellular exchange of nutrients and second messengers. Heterologous intercellular communication was studied in co-cultures of articular chondrocytes and HIG-82 synovial cells by measuring mechanically induced cytosolic changes in Ca2+ ion levels by digital fluorescence video imaging. In confluent co-cultures, mechanical stimulation induced intercellular Ca2+ waves that propagated to both cell types with similar kinetics. Intercellular wave spreading was inhibited by 18α-glycyrrhetinic acid and by treatments inhibiting the activation of purinoreceptors, suggesting that intercellular signalling between these two cell types occurs both through gap junctions and ATP-mediated paracrine stimulation. In rheumatoid arthritis the formation of the synovial pannus induces structural changes at the chondrosynovial junction, where chondrocyte and synovial cells come into close apposition: these results provide the first evidence for direct intercellular communication between these two cell types.

Acid and neutral sphingomyelinases: roles and mechanisms of regulation

2004 ◽  
Vol 82 (1) ◽  
pp. 27-44 ◽  
Author(s):  
Norma Marchesini ◽  
Yusuf A Hannun
Keyword(s):  
Nitric Oxide ◽  
Molecular Mechanisms ◽  
Caveolin 1 ◽  
Niemann Pick Disease ◽  
Extracellular Stimuli ◽  
Niemann Pick ◽  
Hydrolysis Of ◽  
Pick Disease

Ceramide, an emerging bioactive lipid and second messenger, is mainly generated by hydrolysis of sphingomyelin through the action of sphingomyelinases. At least two sphingomyelinases, neutral and acid sphingo myelinases, are activated in response to many extracellular stimuli. Despite extensive studies, the precise cellular function of each of these sphingomyelinases in sphingomyelin turnover and in the regulation of ceramide-mediated responses is not well understood. Therefore, it is essential to elucidate the factors and mechanisms that control the activation of acid and neutral sphingomyelinases to understand their the roles in cell regulation. This review will focus on the molecular mechanisms that regulate these enzymes in vivo and in vitro, especially the roles of oxidants (glu ta thi one, peroxide, nitric oxide), proteins (saposin, caveolin 1, caspases), and lipids (diacylglycerol, arachidonic acid, and ceramide).Key words: sphingomyelinase, ceramide, apoptosis, Niemann-Pick disease, FAN (factor associated with N-SMase activation).

scholarly journals Stochastic left–right neuronal asymmetry in Caenorhabditis elegans

2016 ◽  
Vol 371 (1710) ◽  
pp. 20150407 ◽  
Author(s):  
Amel Alqadah ◽  
Yi-Wen Hsieh ◽  
Rui Xiong ◽  
Chiou-Fen Chuang
Keyword(s):  
Caenorhabditis Elegans ◽  
Molecular Mechanisms ◽  
Neurological Diseases ◽  
Calcium Signalling ◽  
Model Organism ◽  
Brain Asymmetry ◽  
C Elegans ◽  
Left And Right ◽  
Left Right Asymmetry ◽  
Neuronal Asymmetry

Left–right asymmetry in the nervous system is observed across species. Defects in left–right cerebral asymmetry are linked to several neurological diseases, but the molecular mechanisms underlying brain asymmetry in vertebrates are still not very well understood. The Caenorhabditis elegans left and right amphid wing ‘C’ (AWC) olfactory neurons communicate through intercellular calcium signalling in a transient embryonic gap junction neural network to specify two asymmetric subtypes, AWC OFF (default) and AWC ON (induced), in a stochastic manner. Here, we highlight the molecular mechanisms that establish and maintain stochastic AWC asymmetry. As the components of the AWC asymmetry pathway are highly conserved, insights from the model organism C. elegans may provide a window onto how brain asymmetry develops in humans. This article is part of the themed issue ‘Provocative questions in left–right asymmetry’.

scholarly journals Polar relaxation by dynein-mediated removal of cortical myosin II

2020 ◽  
Vol 219 (8) ◽  
Author(s):  
Bernardo Chapa-y-Lazo ◽  
Motonari Hamanaka ◽  
Alexander Wray ◽  
Mohan K. Balasubramanian ◽  
Masanori Mishima
Keyword(s):  
Recent Work ◽  
Molecular Mechanism ◽  
Molecular Mechanisms ◽  
Myosin Ii ◽  
Cell Cortex ◽  
Cleavage Furrow ◽  
Contractile Ring ◽  
C Elegans ◽  
Polar Cell

Nearly six decades ago, Lewis Wolpert proposed the relaxation of the polar cell cortex by the radial arrays of astral microtubules as a mechanism for cleavage furrow induction. While this mechanism has remained controversial, recent work has provided evidence for polar relaxation by astral microtubules, although its molecular mechanisms remain elusive. Here, using C. elegans embryos, we show that polar relaxation is achieved through dynein-mediated removal of myosin II from the polar cortexes. Mutants that position centrosomes closer to the polar cortex accelerated furrow induction, whereas suppression of dynein activity delayed furrowing. We show that dynein-mediated removal of myosin II from the polar cortexes triggers a bidirectional cortical flow toward the cell equator, which induces the assembly of the actomyosin contractile ring. These results provide a molecular mechanism for the aster-dependent polar relaxation, which works in parallel with equatorial stimulation to promote robust cytokinesis.

Smuggle tau through a secret(ory) pathway

2021 ◽  
Vol 478 (14) ◽  
pp. 2921-2925
Author(s):  
Hao Xu (徐昊)
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurodegenerative Diseases ◽  
Recent Work ◽  
Molecular Mechanisms ◽  
Binding Protein ◽  
Nerve Cells ◽  
Transmembrane Domains ◽  
Tau Pathology ◽  
Microtubule Binding

Secretion of misfolded tau, a microtubule-binding protein enriched in nerve cells, is linked to the progression of tau pathology. However, the molecular mechanisms underlying tau secretion are poorly understood. Recent work by Lee et al. [Biochemical J. (2021) 478: 1471–1484] demonstrated that the transmembrane domains of syntaxin6 and syntaxin8 could be exploited for tau release, setting a stage for testing a novel hypothesis that has profound implications in tauopathies (e.g. Alzheimer's disease, FTDP-17, and CBD/PSP) and other related neurodegenerative diseases. The present commentary highlights the importance and limitations of the study, and discusses opportunities and directions for future investigations.

Signal-Transduction Pathways that Regulate Smooth Muscle Function II. Receptor-ion channel coupling mechanisms in gastrointestinal smooth muscle

2005 ◽  
Vol 288 (4) ◽  
pp. G598-G602 ◽  
Author(s):  
Hamid I. Akbarali
Keyword(s):  
Signal Transduction ◽  
Smooth Muscle ◽  
Ion Channels ◽  
Intracellular Signaling ◽  
Molecular Mechanisms ◽  
Second Messengers ◽  
Gastrointestinal Smooth Muscle ◽  
Smooth Muscle Function ◽  
Muscle Excitability ◽  
Coupling Mechanisms

Regulation of membrane ion channels by second messengers is an important mechanism by which gastrointestinal smooth muscle excitability is controlled. Receptor-mediated phosphorylation of Ca2+ channels has been known for some time; however, recent findings indicate that these channels may also modulate intracellular signaling. The plasmalemma ion channels may also function as a point of convergence between different receptor types. In this review, the molecular mechanisms that link channel function and signal transduction are discussed. Emerging evidence also indicates altered second-messenger modulation of the Ca2+ channel in the pathophysiology of smooth muscle dysmotility.

scholarly journals Nicotinic acid adenine dinucleotide phosphate-mediated calcium signalling in effector T cells regulates autoimmunity of the central nervous system

Brain ◽  
2010 ◽  
Vol 133 (7) ◽  
pp. 1930-1943 ◽  
Author(s):  
Chiara Cordiglieri ◽  
Francesca Odoardi ◽  
Bo Zhang ◽  
Merle Nebel ◽  
Naoto Kawakami ◽  
...  
Keyword(s):  
Central Nervous System ◽  
T Cells ◽  
Nervous System ◽  
Nicotinic Acid ◽  
Calcium Signalling ◽  
Effector T Cells ◽  
The Central Nervous System
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